- Text
- Variance,
- Population,
- Analysis,
- Estimated,
- Estimate,
- Sizes,
- Scores,
- Dividing,
- Cutoff,
- Participants,
- Statistical,
- Reasoning,
- Psychology

A. 2 • B. 3 • C. 40 • D. 41 Question 32 of 40 2.5/ 2.5 Po**in**ts If you were to use a "signal-noise" analogy to expla**in** the structural model, you could say that "signal" represents: • A. the between-groups population variance estimate. • B. the with**in**-groups population variance estimate. • C. the total population variance estimate. • D. degrees of freedom. Question 33 of 40 2.5/ 2.5 Po**in**ts In an analysis of variance with a between-groups population variance estimate of 30 and a with**in**-groups estimate of 25, what is the F ratio? • A. 25 / (30–25) = 5.00 • B. (30–25) / 30 = 0.17 • C. 25 / 30 = 0.83 • D. 30 / 25 = 1.20 Question 34 of 40 0.0/ 2.5 Po**in**ts The formula "Σ(M–GM)²/dfBetween" is used to compute: • A. the F ratio for a repeated measures design. • B. the between-groups sum of squared deviations. • C. the estimated variance of the distribution of means. • D. the between-groups estimate of the population variance. Question 35 of 40 2.5/ 2.5 Po**in**ts If a research article reports that "The mean performance scores for the Normal Sleep, Reduced Sleep, and No Sleep groups were 18.0, 16.6, and 15.6, respectively, F (2, 36) = 2.95, p < .05," the most accurate conclusion is that: • A. people who get no sleep perform significantly worse than people who sleep a reduced amount. • B. people who get no sleep perform significantly better than people who sleep a normal amount.

• C. the three groups do not all come from populations with the same mean, although it is not clear which population means are different. • D. conclusions about the relationship between amount of sleep and performance cannot be drawn from these results. Question 36 of 40 2.5/ 2.5 Po**in**ts "S²With**in**" equals: • A. the sum of squares with**in** each group. • B. the square root of the standard with**in**-groups deviations from the mean. • C. the squared variance with**in** groups. • D. the population variance estimate based on the variation with**in** each of the groups. Question 37 of 40 2.5/ 2.5 Po**in**ts Analysis of variance should be conducted only when: • A. sample sizes are greater than 30 per group. • B. sample sizes are smaller than 30 per group. • C. population variances can be assumed to be equal. • D. population sizes are approximately equal. Question 38 of 40 0.0/ 2.5 Po**in**ts Each score's deviation from the grand mean represents: • A. true variation. • B. measurement error. • C. both true variation and measurement error. • D. neither true variation nor measurement error. Question 39 of 40 2.5/ 2.5 Po**in**ts Ann conducts a study, and f**in**ds that the estimated population variances for the groups are 12.8, 16.3, 15.1, and 19.9. What is the with**in**-groups estimate of the population variance? • A. (12.82 + 16.32 + 15.12 + 19.92) / (4 – 1) = 351.18 • B. (12.82 + 16.32 + 15.12 + 19.92) / 4 = 263.39 • C. (12.8 + 16.3 + 15.1 + 19.9) / (4 – 1) = 21.37 • D. (12.8 + 16.3 + 15.1 + 19.9) / 4 = 16.03 Question 40 of 40 2.5/ 2.5 Po**in**ts In the formula, Σ(M–GM)²/dfBetween, "GM" is the:

- Page 1 and 2: PS390 Statistical Reasoning in Psyc
- Page 3: B. can be figured by F/dfWithin.